Recorder



March 13, 1934. E. E. TALIAFERRO 1,950,879

' RECORDER FiledNov. 10, 192 2 Sheets-Sheet 1 ATTORNEY Marcia 13, E. E. TALIlAlT-"EWRO fl fim RECORDER Filed Nov. 10, 1928 2 Sheets-Sheet 2 Patented Mar. 13', 1934 UNITED STATES l,95t,87t

PATENT OFFICE 20 Claims.

This invention relates to the art of recording sound and has particular reference to a process and apparatus for the production of a sound record film or tape adapted for use in connection with a movingpicture projector.

In accordance with the present invention, the sound record is made on a tape which is driven mechanically by the operating mechanism of the camera, so that the sound record tape and the picture film are driven synchronously at the same or proportional rates. An important advantage of this mode of producing .the sound record resides in the facility with which cut outs, fill ins or other adjustments may be made without affecting the syn'ch'ronism between the sound and the picture. For this purpose, the tape and the film will be provided with duplicate longitudinal- 1y spaced markings by means of which the cut outs and fill'ins of the tape can be accurately made with reference to those of the film so that synchronism between the two will be perfectly preserved.

Une of the important objects of the invention is to provide a sound record tape of the above mentioned character having sound record indentations in an edge thereof adapted to coact with a reproducing stylus and having its edge out away between sound records to a depth sumcient till to clear the stylus, whereby during silent periods the reproducing stylus will not engage the tape and therefore will not cause undesirable noises.

, Another object of the invention is to provide a process of forming sound record indentations in an edge of a tape which will correspond with great accuracy to the sound waves by which the record is produced. A preferred process consists in forming the record indentations in a fusible tape by means of heat applied at the points of contact between the sound responsive element and the tape. This method eliminates almost entirely resistance to the movements of the sound responsive element and results in a clean smooth record preserving with remarkable fidelity the fundamentals and overtones of the original sound.

Various other objects and advantages of the invention will become apparent hereinafter.

Referring to the accompanying drawings:

Figure l is a. view in side elevation of an apparatus adapted to make a'sound record in accordance with the invention;

Figure 21s a plan view of the tape support;

Figures 3 and 4 are detail views illustrating a modification in the apparatus shown by Figure 1.

Figures is a side elevation of a modified form of the apparatus.

4 .29 having a rubbing contact with the end of shaft Referring first to the form of the invention illustrated by Figure 1: The recording mechanism is mounted on a frame 10 of any suitable-construction. The mechanism isintended to be operated in synchronism with a moving picture 60 camera adapted to make a photographic record of the scene and action and in order that abso lute accuracy in synchronism may be preserved at all times the sound record tape is driven mechanically by the mechanism which operates the es camera film. For this purpose, Figure 1 shows a driving shaft 11 which is adapted to be connected by a flexible shaft, or other suitable transmis sion, with a driven member of the camera mechanism. Fixed to shaft ll is a pinion l2 meshing lid with a gear 13 fast on a shaft lit having a Worth 15 engaging a worm wheel on a vertical shaft in. Secured to the upper end of shaft 16 is a sproclret wheel 17 the teeth of which engage regularly spaced perforations formed centrally in a tape tit? 18 in one edge of which the sound record is to be formed. Tape 18 is carried by reels A and l-l which are housed respectively in drums l9 and. 20, the feed being from A to B. There is also provided a guide pulley 21 for the tape in its passage to and from the reel A. Reels A and B are driven frlctionally to take up and rewind the tape by suit able drive connections not herein shown, as they form no part of the present invention.

In accordance with the preferred form of the an invention, the sound record is formed on the edge of the tape, which is made of easily fusible ma terial, by means of an electrically heated ele ment which is caused to vibrate in correspondence with the sounds to be recorded, the record being thus made by fusing indentations into the edge of the tape as the latter is fed'past the said electrically heated element. As shown inl igure 1, this electrically heated vibrating element. is in the form of a rotating electrode 22 having tapering sides which converge to a sharp periphery. This electrode, which may be of any suitable material such as platinum, is fixed to the outer extremity of a shaft 23 which is journaled in iiisulated bearings 2t and 25 carried by a frame 26, the latter being pivoted at 2'7 in lugs 28 of the main frame 10. A source of electric current, not shown, is adapted to be connected to shaft 23 and electrode 22 by means of a spring finger ted'guide block 34 through which the tape is drawn. The source of current should be capable of delivering a comparatively large volume of current at moderate voltage, and may be a battery having a low internal resistance. The tape is intended to be thin, about the thickness of writing paper, and should be composed of a low melting alloy. It will be clear therefore that whenever the electrode 22 engages the tape the circuit will be completed and current will flow in sufilcient volume between the contacting points to fuse instantly the material of the tape adjacent these points. I have found in practice that thefusion of the tape leaves an absolutely smooth record indentation and occurs so instantaneously that practically no resistance is offered tot-he vibratory movements of the electrode, so that the latter is enabled to execute its movements in exact correspondence with the sound waves by which it is actuated through the medium of a diaphragm, as will hereinafter be described.

The electrode 22 is adapted to be rotated slowly for the purpose of continuously changing its contact point and thus maintaining a bright clean contact. For this purpose I provide a drive connection between shaft 23 and drive shaft 14, comprising grooved pulleys 35 and 36, respectively fixed to said shafts, and a belt 37 passing over said pulleys. It should be observed that pulley 35 is located in the pivot axis of frame 26, so that the vibratory movement of said frame will not afiect these drive connections.

The sound waves to be recorded are received by a diaphragm 38 which is secured in the enlarged end of a sound transmission tube 39 secured in an upright of the main frame. Connected to the center of this diaphragm is an arm 40 which is pivoted to the frame 26 at 41 and which is adapted to be clamped in adjusted positions on said frame by a clamp screw 42. Screws 43 are provided for adjusting arm 40 with respect to frame 26, and a general adjustment for the frame is provided by screws 44. By means of these adjusting devices, electrode 22 can be placed accurately with respect to the edge of the tape.

The sound record tape in accordance with my invention is adapted to move continuously with the camera film, either at the same rate or at a proportional rate which remains fixed during the entire operation. A record tape thus produced can of course, be easily cut and adjusted for cut outs and fill ins, as required for the picture film, by providing the film and tape with corresponding markings, which will enable the tape to be adjusted in exact accordance with the film, so

that synchronsm between the tape and film will be preserved in reproducing.

There are of course, considerable periods of time during the taking of the picture when no sounds are to be recorded and yet during these periods the tape must be fed at the same rate in order to preserve synchronsm. It is desirable that the edge of the tape at the intervals corresponding tothese silent periods be depressed or cut away, so as not to engage the stylus of the reproducing mechan sm and thus cause undesirable sounds or noises. I have, therefore, provided means for automatically melting away the edge of the tape during silent intervals. The means shown for this purpose comprises an armature 45 secured to upper end of an arm 46 which is pivoted on arm 40 at 47 and held in any desired adjusted position by screws 48. Armature 45 is thus supported-in proximity to the poles of a magnet 49 which is fixed to an overhanging arm 50 integral with the main frame 10. The coilsor magnet 49 are connected by conductors 51 to the coils of a sensitive relay 52, the armature of which is fixed to a contact lever 53 adapted to close a circuit, when the relay is deenergized, including a battery 54, conductors 55 and the co ls of a magnet 56. Magnet 56 actuates an armature on one end of a lever 5'7 pivoted at 58 'to the main frame. The other end of this lever carries a slotted pin 59 through the slot of which the tape 18 travels;

From the foregoing it will be clear that during the reception of sound, the armature 45 will vibrate in front of the poles of magnet 49, varying the magnetic reluctance of said magnet and thereby inducing alternating currents in the circuit including the coils of this magnet and the coils of relay 52. During the reception of sound therefore relay 52 will attract its armature and hold open the circuit of magnet 56. When however the diaphragm 38 ceases to vibrate, current will no longer be induced in the circuit of relay 52 and the contact lever 53 will close the circuit of magnet 56. Magnet 56 will then attract its armature and lift the slotted pin 59 and with it that portion of the tape which passes beneath the. electrode 22. The degree to which the tape is lifted can be regulated by adjusting screw 60 which is connected to the slotted pin 59 and controls the vertical position of the latter with respect to the lever. The lever is also adapted to be adjusted by screws 61 and 62. When the tape is thus raised during the silent intervals its edge will be melted away continuously to a depth sufficient to cause the edge of the tape to be out of contact with the reproducing stylus.

Instead of generating the heat for cutting the tape by passing a current through the sound responsive electrodeand the tape, I may use a heated member or filament, which is constantly heated to a red temperature, the filament taking the place of a rotary electrode. Such a means for cutting the sound record indentations is particularly suitable for use with a tape formed of non-conducting material, such as a hard rubber composition or other suitable composition. Figures 3 and 4 illustrate a modified form of this character. As shown, a filament 100 in the form of a loop and composed of metal not readily oxidizable at a red heat temperature is supported at the end of frame 26'. Current is passed through the filament from a suitable source by means of conductors 101 and brushes 102, the latter having a rubbing contact with the conductors at points substantially on the pivotal axis 27 of frame 26. The thin and readily fusible tape 18' is instantly fused or burned by the heated filament 100 at the points of contact, and will therefore offer a negligible resistance to the vibratory movements of the filament.

According to the modification shown in Figure 5, the record is formed in the tape by means of a rapidly rotating cutter 102, that is, in this form the record indentations are made by cutting the 1 frame 26. Pulley 105 is driven by a large pulley 106 on the armature shaft of an electric motor 107, and is thereby given a high speed of rotation. The rapidly rotating cutter 100 will cut away the material of the tape at such a high rate as to eliminate resistance .to the vibratory move- 1% ments of the cutter imparted by its connections to the diaphragm 38. The tape passes from the cutter 100 to a rotary .brush 108 which is driven by a pulley 109 having a driving connection (not shown) with a, pulley 110 on the armature shaft of motor 107. This brush cleans and polishes the indentations formed in the tape and may be used with a mild abrasive. A similar brush may be used in connection with the apparatus shown in Figure 1, also to clean the sides of the tape.

Now having fully described my invention, what I claim as new and desire to secure by Letters Patent of the United States is:

1. The method of forming a sound record in .a fusible tape of current conducting material,

which consists in causing an element to vibrate against an edge of the tape in response to sound waves, drawing the tape past said element at a uniform rate and passing current through the tape to the element at the point of contact be tween the element and tape to heat said element so as to fuse indentations in the edge of the tape in correspondence with the sound waves.

2. The method of forming a sound record in a fusible metal tape, which consists in causing an element to vibrate against an edge of the tape in response to sound waves while simultaneously drawing the tape past said element at a uniform rate and passing an electric current between the element and tape to generate heat at the point of contact.

3. A sound record tape adapted for use in combination with a moving picture projector, said tape having indentations in its edge forming sound records adapted to coact with a reproducing stylus and having its edge cut away at intervals corresponding to silent periods to a depth suflicient to clear said stylus.

d. A sound recording apparatus, comprising in combination a recordreceiving blank and means for moving the blank at a uniform rate past a point, a pivoted rotating element adapted to vibrate against the blank, means including 2. dia phragm connected to said element so as to cause said element to vibrate and form sound record indentations insaid blank at depths correspond ing to the sound impulses and means for causing said element t6 cut away said blank to a depth greater than said indentations, electrical means responsive to movement of the diaphragm for rendering said last mentioned means inoperative.

5. A sound recording apparatus comprising, in combination with a tape and means for moving the same 'longitudinal1y at a uniform rate, a pivoted rotating element adapted to vibrate against an edge of the tape, a diaphragm connected to said element, and means for applying heat at the point of contact between the element and tape to fuse a sound record in said edge. 6. A sound recording apparatus comprising, in combination with a metal tape and means for moving the same longitudinally at a uniform rate, a pivoted element adapted tovibrate against an edge of the tape, a diaphragm connected to said element, and means for passing an electric current between said element and tape to generate heat at the point of contact and fuse record indentationsin said edge.

7. A sound recording apparatus comprising, in

combination a,tape and means for moving the same longitudinally at a uniform rate, a pivoted element adapted to vibrate against and indent an edge of thetape, a diaphragm connected to said element so as to cause said element to vibrate to thus form sound record indentations in said 'edge, and means controlled by said diaphragm for moving the tape and element together when the diaphragm is at rest to causesaid element to cut away said edge at a uniform depth during silent periods.

8. A sound recording apparatus comprising, in combination with a tape and means for moving the same longitudinally at a uniform rate, a pivoted element adapted to vibrate against an edge of the tape and to serrate said edge, a diaphragm connected to said element so as to cause ,said element to vibrate to thus for-msound record indentations in said edge, and automatic means for moving said tape and said element toward each other during silent periods to cause said element to cut away said edge at uniform depth.

9. A sound recording apparatus comprising, in

combination with a tape and means for moving the same longitudinally at a uniform rate, means for forming sound record indentations in the edge of said tape and automatic means for cutting away said edge to a uniform depth during silent periods.

10. A sound recording apparatus comprising, in combination with a tape and means for moving the same longitudinally at a uniform rate, a pivoted element adapted to vibrate against and serrate an edge of the tape, a diaphragm connected to vibrate said element so as to cause said element to form sound record serrations in said edge, and means controlled by said diaphragm to move the tape towards said element when the diaphragm is at rest to cause said element to cut away the edge to a uniform depth during silent periods.

11. A sound recording apparatus comprising, in combination with a tape and means for moving the same longitudinally at a uniform rate, a pivoted element adapted'to vibrate against and indent an edge of the tape, a diaphragm connected to said element so as to cause the latter to vibrate to form sound record indentations in said edge, means for moving the tape transversely towards said element, a magnet for operating said means, and automatic means for closing the circuit of said magnet when the diaphragm is at rest.

12. A sound recording apparatus-comprising, in combination with a tape and means for moving the same longitudinally at a uniform rate, a diaphragm, an element connected to said diaphragm so as to vibrate against an edge of thetape and adapted to form a sound record therein, and

means for moving said tape transversely towards said' element during silent periods, said means comprising a permanent magnet, an armature vibrated by said diaphragm adjacent the poles of said magnet, a winding on said magnet, a relay connected to said winding, an electro-magnet the circuit of which is closed when said relay is deenergized, a lever operated by said electromagnet and a connection between said tape and lever.

13. 'In combination, an element, a tape of current carrying material, means for moving said tape past said element at a uniform speed, means for causing said element to vibrate against an edge of the tape, a source of current, and a circuit iiicludingsaid source, said element and said edge of said tape, said source of currentbeing of suiiicient amperage tofuse the tape when the circuit is closed by said vibrating element.

I I l, Ina sound recordery-rneans for supporting a record blank, means for operating on'said blank in response to sound waves, electro-magnetic means for changing the operating depth of said i as operating means to cut a uniform thickness of material from the blank, means vibrating in response to sound waves for rendering said electromagnetic means inoperative.

15; In a sound recorder, means for supporting and advancing a record tape, means for serrating the edge of a tape including a sound responsive vibratory element, means for generating a current by said element, an electro-magnetically operated means for changing the'cutting depth of the serrating means and means whereby said current renders the electro-magnetically operated means inoperative.

16. A'recording apparatus, comprising, in com- .bination, a tape and means for moving the same longitudinally by a given point, means at said point for forming indentations in an edge of said tape as it passes, said means including an element adapted to vibrate against said edge, and means for vibrating. said element, electro-magnetic means for drawing said element and said tape togetherand thereby causing said element to cut away the edge at a uniform depth, a circuit for said electro-magnetic means including a source of current and means for opening said circuit in response'to movement of said means for vibrating whereby the edge is cut away only when the means for vibrating is stationary.

1'7. In combination with an electrical circuit including an impulse recording tape of conducting material, a source of current and an element adapted to conduct current to said tape, means for moving the tape past said element and impulse responsive means for causing the engageq ment of said element and said moving tape whereby current flows thru said circuit and heats the element and point of engagement of said tape to thereby cut away the edge of the tape to varying depths in accordance to the action of said engagement causing means.

18. I he method of forming a sound record in a fusible metal tape, which consists in causing an element to vibrate against an edge of the tape in response to sound waves, causing relative uniform movement of said element and tape in a line substantially normal to the line of vibratory motion of said element and passing electric current between the element and tape to generate heat 

